GVA LED LCD picture dissapears

[wrx884]

Have been given a (no real brand name) GVA LED LCD to try see if I can repair. Its probably not worth the time and effort but hey its good learning experience for myself :P

TV model: GVADLED32C
Main board: TP.SIS231.P83

Symptom: TV turns on and after 5-10mins the picture will fade from right to left to a black blank screen.

I noticed the back lights must work as the TV does display some sort of black lighting on screen as soon as I turn it off it goes totally black like it should.

After it goes into this state I cant turn the TV off and on again to get a picture, I would have to leave it for say 24 hours or so before I can get a picture to come back up. Does this sound like failing caps? I have checked these and they look fine (not tested with an ESR meter yet) on the outside but being the type of cheap arse TV it is they are probably cheap and nasty caps?

There are no stickers to show testing values that I can find but can see on the back of the main board some labels to certain pin outs ect... so mayb u guys can help from these?















I can find replacement main boards for say $40 but these are from different branded TV's (same main board number TP.SIS231.P83) hitachi, would these be plug and play or will they have a different TV's firmware installed on it and wont work straight off the batt?

[Hamie]

Re: GVA LED LCD picture dissapears

Ah the super reliable powersupply-mainboard-tcon combi board!
What could possibly go wrong!
That tv is an absolute mutant and should be put out of existence.

To answer your question, yes it's the same mainboard used in hitachi, technika and many others. It won't matter what one.
It's not failed caps, its probably bad solder under the processor, corrupt EEPROM flash.

Since it seems to be heat related you could try using a can of freeze spray and see if you can freeze a component to get it to last longer.

[wrx884]

Re: GVA LED LCD picture dissapears

LOL yep this one

Processor being the CPU yeah? I can try reflowing the CPU with my bga rework machine tho how do the larger caps go with heating the board up to 170-220*? must they be removed 1st? this mother board is thin and I can see its not 100% flat with no real board support so it wouldnt take much to bend/twist naturally breaking these solder joins under normal use.

If its eeprom flash I think that's far from my capabilities tho where would I find where its stored?

Ive got freeze spray on hand what are the main components to try freeze 1st? is it best I turn the TV on and when I get picture feel for components which get warm/hot and then just spray them? sounds like I need something that can display thermal imaging that would be handy.

[wrx884]

Re: GVA LED LCD picture dissapears

Ah the super reliable powersupply-mainboard-tcon combi board!
What could possibly go wrong!
That tv is an absolute mutant and should be put out of existence.

To answer your question, yes it's the same mainboard used in hitachi, technika and many others. It won't matter what one.
It's not failed caps, its probably bad solder under the processor, corrupt EEPROM flash.

Since it seems to be heat related you could try using a can of freeze spray and see if you can freeze a component to get it to last longer.

Does the factory order number need to be the same as mine? I have a seller suggesting that if this is not the same the T-con will be different so will the firmware so it wont work if they are not? or could he just be saying this to cover his arse in case it doesn't work?

[RJARRRPCGP]

Re: GVA LED LCD picture dissapears

I think I just saw a typo!

[freakaftr8]

Re: GVA LED LCD picture dissapears

My bet would be on a BGA solder under the main cpu.

[wrx884]

Re: GVA LED LCD picture dissapears

I think I just saw a typo!

great eyes? but this does not help anyone sorry pointless post

[wrx884]

Re: GVA LED LCD picture dissapears

My bet would be on a BGA solder under the main cpu.

can u put any insight on if I need to remove caps before attempting a reflow or even re-ball on the CPU? or will they be fine

[freakaftr8]

Re: GVA LED LCD picture dissapears

I have had luck with reheating a main board the only thing that I have run across in some models are the component sockets melting slightly. It depends on what kind of composite plastic they're made of. You could attempt a heat gun on the main processor or you could attempt some freeze spray on the processor to see if that is indeed the problem. You should see the screen disappear immediately after you heat or freeze components on the board until you get to the right part.

[freakaftr8]

Re: GVA LED LCD picture dissapears

I use this method. Oven at 450 f or 232.2 c for 8 minutes.

Then open the door and turn the oven off and let it sit for another 15 minutes before you pick it up

[wrx884]

Re: GVA LED LCD picture dissapears

I use this method. Oven at 450 f or 232.2 c for 8 minutes.

Then open the door and turn the oven off and let it sit for another 15 minutes before you pick it up

I have a BGA rework station id prefer to use that, I don't believe in heat gun methods unless they are only used for temp data retrieval and that's it. heat guns should only be used to strip paint LOL.

I guess the question I asked so its only the plastics I need to be carful of and not so much the elec caps? I can mask these with alu tape as my rework station uses IR so it should reflect most of the heat where its not needed.

[wrx884]

Re: GVA LED LCD picture dissapears

Is the firmware stored on the IC (I think its BGA actually) that's directly above the CPU that's rectangular shaped?

if firmware is an issue with other motherboards that I can find but are not the exact same as mine shown, could I simply swap over that small chip? I guess that's provided this board does have a good flash tho but can I rule out bad flash somehow or is the only way to do that is to read whats on it?

[Klevi]

Re: GVA LED LCD picture dissapears

Hi to all.
Can someone help me with some smd value please?
My power board was burned out from high voltage.

[Klevi]

Re: GVA LED LCD picture dissapears

Have been given a (no real brand name) GVA LED LCD to try see if I can repair. Its probably not worth the time and effort but hey its good learning experience for myself :P

TV model: GVADLED32C
Main board: TP.SIS231.P83

Symptom: TV turns on and after 5-10mins the picture will fade from right to left to a black blank screen.

I noticed the back lights must work as the TV does display some sort of black lighting on screen as soon as I turn it off it goes totally black like it should.

After it goes into this state I cant turn the TV off and on again to get a picture, I would have to leave it for say 24 hours or so before I can get a picture to come back up. Does this sound like failing caps? I have checked these and they look fine (not tested with an ESR meter yet) on the outside but being the type of cheap arse TV it is they are probably cheap and nasty caps?

There are no stickers to show testing values that I can find but can see on the back of the main board some labels to certain pin outs ect... so mayb u guys can help from these?















I can find replacement main boards for say $40 but these are from different branded TV's (same main board number TP.SIS231.P83) hitachi, would these be plug and play or will they have a different TV's firmware installed on it and wont work straight off the batt?

Hi could you please let me know some value.
I have some buried resistances and caps.

[Alastair E]

Re: GVA LED LCD picture dissapears

TBH--With that sort of damage--On a combo mutant, where no schematics available, be cheaper and quicker in long run to just replace the whole board.

It wont be just those parts that have been blown to bits, it'll be a whole lot more--prolly the chips too....

[wrx884]

Re: GVA LED LCD picture dissapears

Hi could you please let me know some value.
I have some buried resistances and caps.

sure i'll have a look when I get it back out of the TV at some time. can u list the references to the components so I know which ones u need exactly?

seems these are hard to find even a replacement board for them so these TV's are pretty much a throw away jobby. I still haven't bothered to try re-balling the CPU yet.

[Anselme]

Re: GVA LED LCD picture dissapears

Can someone help me with TV eeprom data or firmware le-22gy14r+DVD panel number TP. SIS231.PA501, bin file please it's urgent thanks in advance

[maxvalutech]

Re: GVA LED LCD picture dissapears

Hi also from Oz. The GVA was marketed by Good Guys chain. I was given a 50" recently picture all purplish on the blacks - all settings out of wack so tried several times to change them but always went back to previous then I just clicked on reset alone and all came good and going well. Also got a 50" Hitachi that supposedly only started about 1 in 10 attempts - found battery box in remote had a loose end so repaired that first now TV starts first time every time both with remote and set control buttons so the people must never have tried those.
But my question is where do you get the freeze spray, brand etc as I can never find any. Cheers.

[dskall]

Re: GVA LED LCD picture dissapears

Usually where ever they sell electronics they will sell air duster. You just have to turn it upside down.

[budm]

Re: GVA LED LCD picture dissapears

http://www.dust-off.com/cleaning-with-dusters
I get my 6-pack from COSTCO.